January 16, 2019


Shannon Kelly, Bureau of Aquaculture


Aquaculture by definition is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other organisms.

The Department of Agriculture (DoAg)’s Bureau of Aquaculture is the licensing/permitting agency for shellfish (hard clams, oysters, mussels) and algae seaweed (kelp) in Connecticut.

DoAg has always viewed the way shellfish growers in Connecticut manage their crops as farming because the ground is worked and monitored.  The bottom is cleaned off prior to oysters being relayed onto it from another lot. 

Oysters are moved to deeper, colder water to slow their growth. They are tumbled to produce a tougher shell and deeper cup.  They are relayed to approved water for natural cleansing and can also be stockpiled for harvest at a later date.

Dried oyster shell—known as cultch—is put down to attract baby oysters that can then be moved to another site.

The Long Island Sound is a waterbody shared by many interests, including commercial/recreational fishing, recreational boating/sailing, kayaking, scuba, snorkel, jet skiing, swimming, birding, and sightseeing. 

Because all must be able to safely use, share, and enjoy this invaluable resource, there is regulatory oversight.

The use of any “structure” in the water column (i.e. bottom netting, bottom cage, hanging cage, floating bags, hatchery, upweller, or longline) requires an application to DoAg, which is reviewed by DoAg, the Connecticut Department of Energy and Environmental Protection (DEEP) and the U.S. Army Corps of Engineers (USACE). 

A Certificate of Operations is needed from DoAg. Other permits may also be needed from DEEP and USACE before work associated with any structure can begin.

Since 2000, when DoAg began keeping a database and actively tracking aquaculture projects, 39 entities (commercial companies, town shellfish commissions, schools, NOAA’s National Marine Fisheries Service, and DoAg) have applied for an Aquaculture Certificate to use primarily bottom cages, floating cages, upwellers, bottom netting, and hatcheries. Certificates have been issued to 35 entities.

Traditionally, hard clams and oysters have been grown on the bottom and harvested using dredges, relying on nature to produce enough product year after year.

Over time, and with innovation, the idea of growing shellfish from seed in a hatchery was developed to produce a more reliable supply of shellfish.  In Connecticut there are currently three hatcheries producing seed oysters with several more in the planning stages. 

Once the baby oysters/clams seed reach a certain size, they are moved out of the hatchery and into a system of individual cylinders, or silos, through which ocean water is pumped, known as an upweller.

The upweller can be incorporated into/underneath a dock or moored alongside a floating dock.  Having upwellers allows the company to purchase larger size seed, increasing the survival rate. 

There are currently 12 companies permitted to have and use upwellers in Connecticut, with several more in the planning stages.

Because hard clams live in the mud, it is difficult to grow them in cages. However, they can be grown in the bottom under predator netting. 

The netting is spread on the bottom similar to row covers and held to the bottom with rebar around the edges. 

This prevents predator crabs from eating the baby clams. There are currently three companies permitted to use predator netting for growing hard clams in Connecticut.

Bottom cages, similar in size and shape to lobster cages, are used to grow and hold oysters.  The use of cages produces a more desirable and reliable product. 

Using cages makes it easier to locate and handle the oysters and harvest the exact number needed to fill orders.  The use of cages does, however, require a different boat design because dredges are not used.

An onboard crane system is needed to lift the cages on deck.  The cages can either be emptied onsite, or the whole cage can be brought back to shore. Cages are set either individually with one buoy per cage or several on the same ground line with one buoy per line.

There are currently 23 companies permitted to use bottom cages to grow oysters in Connecticut.